5. Remove sheet from oven. Spoon rosemary-fat mixture over potatoes and turn again. Continue to roast until potatoes are well browned and rosemary is fragrant, 3 to 5 minutes. Season with salt and pepper to taste. Serve immediately.

Saving Fat for Cooking

Saving the leftover fat from duck is easy to do. Pour the warm fat through a fine-mesh strainer into a Mason jar and discard any solids.

Alternatively, let the fat cool and harden and then scoop it into the jar, leaving any solids behind.

Put the lid on the jar, label it, and refrigerate it for up to one month or freeze it for up to six months, adding more fat as desired.

Note: Salt causes zucchini rounds to release excess water. This important extra step helps the zucchini to sauté rather than stew in its own juices. Quarter-inch slices are the perfect thickness.

1. Place zucchini slices in colander and sprinkle with 2 teaspoons salt. Set colander over bowl until about 1/3 cup water drains from zucchini, about 30 minutes. Rinse and thoroughly dry zucchini.

2. Heat oil in large skillet over medium heat. Add onions or shallots; sauté until almost softened, about 3 minutes. Increase heat to medium-high; add zucchini and sauté until golden brown, about 10 minutes.

3. Stir in walnuts and herbs, and season with pepper to taste. Adjust seasonings and serve immediately.